How to Test For a Bad Brake Booster / Brake Booster Testing

In this video show how I test for a bad brake booster and check valve. Testing a brake booster for leaks is pretty easy and doesn't require a bunch of tools. The exact vehicle in this video is a 2002 Toyota Tacoma pickup truck. Enjoy!

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Due to factors beyond the control of the Big Dog50001 Automotive Channel, it cannot guarantee against unauthorized modifications of this information, or improper use of this information. The Big Dog50001 Automotive Channel assumes no liability for property damage or injury incurred as a result of any of the information contained in this video.

The Big Dog50001 Automotive Channel recommends safe practices when working with power tools, in on or around automobiles or other vehicles, automotive lifts, lifting tools, jack stands, electrical equipment, automotive modules and systems, blunt instruments, chemicals, lubricants, or any other tools or equipment seen or implied in this video. Due to factors beyond the control of the Big Dog50001 Automotive Channel, no information contained in this video shall create any express or implied warranty or guarantee of any particular result. Any injury, damage or loss that may result from improper use of these tools, equipment, or the information contained in this video is the sole responsibility of the user and not the Big Dog50001 Automotive Channel.

[BigDog]

Check out The Accord Project videos!

[gvjester]

WOW!! Learned more about brakes in this 10 minute video than in the last ten years! You are the brake GOAT!
MANY THANKS!!

[ryszardjacekrusniak]

It explains EVERY aspect of testing the brake booster. Thank you,

[GunnersRange]

I love the way you explained everything. You did this better than most other sites on YouTube. THANK YOU!

[eddieesquivel]

I had recently replaced a fitting that fixed a vacuum issue (fitting on manifold) that had turned on check engine light. Parts store clerk said it was for brakes and whether I was having issues. We weren't, but the check engine light was on for vacuum issue. Light went away when fitting was replaced, but came back on several days later (I did not reset light, it just turned off when fitting replaced). Diagnostic showed no errors, but history showed brake issue. It's clear now. Video helped explain how vacuum loss could cause the "brake" check engine light issue. Thanks.

[dog]

I know this is an old video but I just want to say dude you just help me out a lot this video will help people for years to come

[dannick]

Thanks Big Dog! Very detailed yet easy to understand, excellent job!

[LeMec]

Just helped me diagnose a the problem. Saved me from buying parts I didn’t need and some frustration. Many thanks!

[QdMaster]

Great job on explaining simply and covering everything, the shops hate you but we DIY people are very grateful! I'm sure you've helped atleast 100k of the 5 million that watched this if not more! God bless brother 😇

[DanOnFire]

I think everybody else has already said it: you do a fantastic job explaining the how and why of each simple test. Thank you!

[lendanhoke]

Very well explained. Appreciate the accurate information! I Wish school teachers knew/explained their curriculum this well.

[bangerftw]

I have to pass a knowledge exam soon to change class as a mechanic and your video are very helpful, you are a great teacher.

[sergedenovo]

BY FAR, the best video on the subject that I have found. Sincere thanks!
Serge in Chicago.
Imma go see!

[HomeMadeBoards]

10/10 mate. Straight to the point, great, simple, yet vital information other channels aren't addressing.

[brianpeacock]

I am an A.S.E. tech and this is an excellent video for b-booster
fault trouble shooting.

[feliperigau]

Very informative! My fluid level was down below minimum but after topping it off the light remained on. The dealership recommended tapping the reservoir to free the measuring arm in the reservoir. IT WORKED!! LIGHT OFF!!

[GMoney-B]

I have bled my brakes 3 times for squishy pedal syndrome. The third time I bled my brakes I used a pressure bleeder and my brakes were great and fine for a couple months until today when the squishy pedal came back. I didn't think it was the master cylinder because it would get better and not come back after bleeding the brakes. Each time it would come back, it would seemingly happen over night.

I did the last test that you described to do that tests your master cylinder, with the engine off. I pumped a bunch of times(6 or 7) to get rid of vacuum in the brake booster, then I held the brake for 15 seconds. My brake pedal held firm and didn't sink, it did do a really weird thing though after 15 seconds of having this very very slow pulsing that would push my foot back very very slightly almost not noticeable. It would push back for maybe 5 seconds in a gradient pulse, and then go back that same amount. Again, my engine was off, and the distance it pushed back was so so so small so I would think it wouldn't be an issue, but I also never expected it to have a gradually sweeping pulse pushing my foot back when the engine was off.

I would think it is air in my system, or a leak? What do you think? If anyone else has any ideas or experience with this, I would really appreciate any expertise! Really wanting my brake gremlins to be stomped out after maybe 4-5 months of this now.

[jimmypage]

Couldn’t have done it better myself excellent video sir! Every possible easy way to check the booster/vacuum/master cylinder system. Thank you

[robertt]

This helped me out and saved me from a $300 repair job. Thank you!

[jimlawson]

I'm wondering if you have any deaf people in your family. The way you communicate through you hands is phenomenal. Thank you.